Evaluation of regulated and unregulated emissions from a diesel powered vehicle fueled with diesel/biodiesel blends in Korea

The emission characteristics of diesel powered vehicles using conventional diesel fuel and six different biodiesel blends at proportions of 1% (B1), 3% (B3), 5% (B5), and 20% (B20) by volume were investigated. The emission tests were performed following the NEDC (New European Driving Cycle) and regulated and unregulated emissions were measured for two vehicles - one equipped with a DOC (diesel oxidation catalyst) and the other equipped with a DPF (diesel particulate filter). Emissions of THC (total hydrocarbon), CO, and PM (particulate matter) generally decreased with increasing biodiesel content in the fuel, while NOx emissions increased slightly in both vehicles. CO2 emissions were virtually identical. The extent of PM reduction in the DPF-equipped vehicle was almost 40 times higher than in the DOC-equipped vehicle. PAH (polycyclic aromatic hydrocarbon) emissions decreased with increasing biodiesel content in the fuel, with average reduction rates of the six biodiesels for particle-phase PAHs compared to the base diesel fuel in the range of 18.2-27.2% and 48.9-79.7% for the DOC- and DPF-equipped vehicles, respectively. Nanoparticle emissions from the DOC- and DPF-equipped vehicles were predominantly in the size range of 25.5-191.1 nm and <25.5 nm, respectively.